1. Field of the Invention
This invention relates to rocket propelled vehicles such as missiles, and more particularly, to arrangements for steering such vehicles by a combination of steering fin control and jet reaction control.
2. Description of the Related Art
Missile control can be effected using a variety of steering schemes. One such scheme involves pivoting the thrust vectoring nozzle of the missile about a pivot point and controlling the direction of its thrust in order to provide steering in a desired direction.
Another method utilizes movable aerofins projecting into the airstream around the missile. This imparts to the missile the necessary forces to change its direction during flight within the earth's atmosphere and thereby effect steering control.
Jet reaction control (JRC) provides yet another method for steering a missile during flight, and is shown in U.S. Pat. No. 5,016,835 of Kranz. This method involves selective firing of jet nozzles disposed radially around the periphery of the missile in order to orient the missile in a desired direction. The fired jets impart an opposing reactive force on the missile and, depending on their arrangement, can serve to produce a change in direction along the yaw, pitch and/or roll axes.
It is also known in the art to effect missile control during flight using a combination of steering methods. One such combination, disclosed in U.S. Pat. No. 5,505,408 of Speicher et al., assigned to the same assignee as the present invention and incorporated herein by reference, relies on both jet reaction control (JRC) and control actuator fins. The two steering schemes operate in conjunction with one another to effect missile control, and yield a particularly advantageous arrangement because in some situations, when the dynamic pressure is low, such as during high attack angles or in a reduced atmosphere, the jet reaction control mechanism can compensate for the diminished effectiveness of the steerable aerofins, avoiding a compromise of missile maneuverability.